4. Discussion

After sampling and testing water from 3 separate locations along the Sungei Ulu Pandan river, we have found the readings for all 9 parameters. They are in order of importance (higher weighting to lower weighting of parameters that affect the water quality index): Dissolved Oxygen, Fecal Coliform, Biochemical Oxygen Demand, pH Value, Nitrates, Total Phosphates, Temperature, Turbidity, Total Dissolved Solids. The readings were then tabulated (see Methods section) and compared against the Q Value charts. We then found out the water quality index for the individual testing sites. Test location A and B both are graded "good", while test location C is marked as "medium". Our results show that there are no visible forms of pollution within our sampling sites and it may be feasible to purify the water for human consumption. It hence tallies with our hypothesis, however with a benefit of a doubt.

Test location A and B are similar in characteristics. They are part of the trench making up the canal of Sungei Ulu Pandan River. They have minimal visible organisms, such as fishes. This could be attributed to the shallowness of the trench and the fact that the area has low tide. They are also not sheltered from direct sunlight, hence water temperatures may range from 32-33 °C. As such, the readings of dissolved oxygen is catergorised as "supersaturation". Such an occurrence may be harmful to certain species of aquatic organisms.

Test location C has a different story. It is the mouth of the Sungei Ulu Pandan River, hence it is the merging of tributaries. Before test location C, there is the above mentioned canal and a smaller stream. They merge before test location C, thus the volume of water drastically increases. It is here that the water current is higher too. Due to the immense depth of the water, one can spot a large amount of fishes and seldomly, terrapins. The dissolved oxygen level dips largely, especially when compared to test location A and B. The dissolved oxygen level is categorised as "poor" (Vernier).

We found that the fecal coliform readings for test location A and B are slightly above permissible standards for swimming. For boating and fishing, they are within range of the permissible limit, with levels lower than 5000/100ml (Vernier). However, the sampled water's usage is prohibited for drinking, or potable water. Permissible levels are 0/100ml (Vernier). For test location C, it is slightly below the permissible limit for swimming and is within range of the permissible limit for boating and fishing. It is too, unsafe for drinking. The optimal temperatures of the waters may have been conducive for the growth of fecal coliform.

We have several areas for improvement. The biggest of them being our sample size. We only conducted one test for all testing locations, meaning that we are unable to take an average over 3 tests. That is desired as it can be more accurate and allows us to confirm our hypothesis with more confidence. Testing was also time consuming, and coupled with other daily activities, we were unable to do more than 1. We could also have taken water samples shortly after a downpour. With that, we are able to see the changes in the readings of the parameters. We could have also used sterile equipment before the collection of water. This prevents any other contamination, besides the one of the sample water. For fecal coliform testing, it would be better if the funnel was rinsed with sterile water more frequently. This allows the isolation of an individual sample of water, and not a mix of all three which may affect the readings. During our collection, we spent too much time recording the data. Bringing pen and paper would be more advisable, transferring the data to another area later in our free time. This all boils down to our planning. With better planning, our collection and experiments can be more systematic and efficient. Reducing the amount of time spent is also to our advantage.

Testing for water quality is essential to our daily lives, as potable water is a necessity for living. We are fortunate that Singapore has excellent water quality for our needs, such as cleaning and drinking. For ourselves, testing of water quality at home is not that feasible. Since the water is of desired drinking quality, we would not have much to test about. However, such skills may come in handy if you have an aquarium. Making sure the water quality is right would ensure healthier living for the fishes. Since our school owns and manages a pond, testing its water quality periodically may be suitable to find out whether the water is optimal. Other factors include whether there are a large amounts of organisms dying or aquatic plants withering. The Public Utilities Board tests for water quality too, before it is piped out to homes or industries (PUB, 2011). This would ensure that the society has water of premium, excellent and utmost safe quality.

For further research, I would suggest taking water samples after a downpour. Similar to it being mentioned above, this would allow us to see changes in the readings for the water quality. By knowing the water quality for both rainwater and Sungei Ulu Pandan's water, we can see which one is more feasible for drinking, or activities such as boating and fishing. With such data, our research would be more in-depth, with lesser doubts to clear. Such a research is a well-rooted one, while ours can be considered a "sapling".